Theoretical research on self-assembly system of molecularly imprinted polymers formed by melamine and trifluoromethacrylic acid

The long-range correction method (WB97XD) was applied to simulate the self-assembly system of the molecularly imprinted polymers via Gaussian 09 software. Melamine (MAM) was taken as the template molecule and trifluoromethacrylic acid (TFMAA) was taken as the functional monomer. The ethylene glycol dimethacrylate, divinylbenzene, pentaerythritol triacrylate, and trimethylolpropane trimethylacrylate were chosen as the cross-linking agents, respectively. The acetonitrile, methanol, dichloromethane, chloroform, toluene, ethanol, and dimethylsulfoxide were taken as solvents, respectively. The bonding situation, the geometry optimization of the different imprinting ratios, the binding energy, the molecular imprinting mechanism between MAM and TFMAA, and the influence of cross-linking agent as well as solvent have been studied. The detailed topological property was also applied to discuss the nature of the imprinting effect. The results indicate that MAM and TFMAA can form ordered compounds via hydrogen bond interaction. The melamine-molecularly imprinted polymers with a molar ratio of 1:6 have the lowest binding energy, the largest amount of hydrogen bonds, and the stable structure in toluene solvent. Divinylbenzene is the best cross-linking agent for the melamine-molecularly imprinted polymers in comparison with others. The study can provide a theoretical reference for the synthesis of the high selectivity melamine-molecularly imprinted polymers.